The present invention concerns a brake caliper for a disc brake.
Such brake calipers for disc brakes are normally produced integrally by a casting process, preferably in a sand-casting process, wherein a preferred material is spheroidal graphite cast iron. The resulting blank casting is then machined by material removal to produce a brake caliper ready for installation. Such one-piece brake calipers made of spheroidal graphite cast iron according to the prior art have proved successful in principle, but have some drawbacks which have adverse effects in particular in the area of application of heavy trucks.
The disadvantages here in particular are the high process costs of the casting process, due to the great complexity of melting the casting material, removing the sand core, targeted cooling following the casting process, and cleaning the raw casting. These costs are only slightly proportional to quantity.
A disadvantage resulting from the principle of the production method of “lost mold casting” lies in the fact that a casting model is essential, so that because of the cost structure of a cast brake caliper, there is a minimum limit quantity for economic production of a cast brake caliper. Costs are also incurred by the runner system, which is admittedly returned to the melt but must be paid for.
In addition, due to the permanent loading of the casting model with molding sand, a casting model is subject to abrasive wear so that after a specific number of molding processes, it must be replaced with a new casting model. This further loads the cost structure of a cast brake caliper.
Furthermore, due to the production principle, a cast brake caliper requires minimum wall thicknesses in order to be reliably castable. This leads, in particular in regions subjected to low loads, to over-dimensioning of the material in relation to strength, leading to disadvantages for cost and weight.
Furthermore, a material-removal process is required to produce a usable brake caliper from a blank casting.
There is thus the need to provide a brake caliper, in particular for vehicle brakes, in particular for truck brakes, which at least partly overcomes the above disadvantages.
EP 0 108 680 A1 discloses a brake caliper made from two shaped components. The upper and lower components of the brake caliper each have central openings. The upper and lower components are each produced from a sheet or strip such that both have a central half-cylinder. Several smaller half-cylinders are formed in the upper and lower components, each spaced from the central half-cylinder. When the two components are joined together, the formed half-cylinders become full cylinders and can receive other components, e.g. the application actuator (hydraulic in this case) or guide pins to guide the movement of the caliper in the axial direction relative to the brake disc.
The disadvantage with the design according to EP 0 108 680 A1 is the lack of precision of the resulting receiver, in particular for guide elements.
In addition, because of the selected structure of the essential structural components, the design of portions with higher mechanical load may not be load-compatible, or only inadequately so. Thus the construction selected in EP 0 108 680 A1 is not usable or only limitedly usable for the truck sector.
The invention is therefore based on the object of providing a method for production of a brake caliper, and providing a brake caliper which avoids the disadvantages above and can be produced economically, process-reliably and hence efficiently.
This and other objects are achieved by the invention in that the housing comprises a base plate, an intermediate plate, a housing shell connecting the base plate and the intermediate plate, and the housing cover. The caliper frame is cut from a sheet metal and shaped, and the housing cover is formed integrally with the caliper frame.
The invention thus creates a brake caliper which has components created by cutting processes, or cutting and shaping processes, or cutting and joining processes, wherein the one-piece caliper frame has a housing upper part which is part of the housing of the application mechanism of the brake disc.
One advantage of a brake caliper which is preferably assembled from several components, produced either by a cutting process or by a combination of a cutting process and a shaping process, is the possibility of being able to design regions with higher or lower loading load-specifically in regard to the wall thickness and selection of material, so that the material of the respective component is optimally utilized. This is achieved e.g. by the use of a tailored blank as a starting product. This flexibility in material choice leads to substantial advantages in the weight balance and cost structure of an assembled brake caliper.
The flexibility with regard to material choice also allows for, in principle, a choice of materials with greater strength and yield strength, wherein the cost structure and above all the weight of the brake caliper can be further optimized. Here, in particular, a low weight, as well as optimum cost structure, is a predominant development target in the vehicle sector, since a higher payload for the vehicle is possible.
Due to the construction of the brake caliper from shaped components, there is a higher number of potential suppliers than for a comparable brake caliper of spheroidal graphite cast iron.
A further essential cost benefit for a brake caliper according to the invention results from the absence of a cost-intensive casting model. Due to the design, in a brake caliper according to the invention, there is no need—at least in part—for machining of a blank by material removal, which brings further cost benefits.
In addition, with a brake caliper according to the invention, the machining of a blank by material removal is not required, leading to further cost benefits.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.